Quantitative and qualitative variability of pea (Pisum sativum L.) protein composition

Smooth and wrinkled pea cultivars were studied to evaluate the protein content of the seeds, the proportion of albumins to globulins and the variability of the vicilin/legumin ratio. Principal components analysis showed a strong negative correlation between albumin and globulin contents. Stepwise discriminant analysis demonstrated that two variables, protein content and vicilin/legumin ratio, divided the samples into smooth and wrinkled cultivars with a percentage of success of 95%. In addition, the vicilin/legumin ratio tended to increase, the lower the protein content is.     

Search for predictors of cooking quality of marrowfat pea (Pisum sativum L) cultivars

The grain from 116 marrowfat pea breeding lines was assessed subjectively using current visual methods and then analysed objectively for L*a*b* colour, hydration capacity and cooking quality. The data show that the current method of selecting genotypes by subjective methods is not able to select marrowfat peas for specific processing uses. However, an objective measure, the ?a* value of the dry grain, was a very good predictor (p < 0.001) for the hydrated and cooked green colour. Cultivars which have a high hydration coefficient may be more suitable for canning and deep frying because they hydrate to a larger size, while cultivars with a high bulk density and a darker green grain are more suitable for use as extrusion products. © 2001 Society of Chemical Industry     

Effect of extrusion cooking on structure and functional properties of pea and kidney bean proteins

Pea (Pisum sativum L cv Ballet) and kidney bean (Phaseolus vulgaris L cv Pinto) seeds were extruded at 148 and 156 °C respectively. Protein solubility at various pH values and in various solvents was determined and analysis of protein fractions was carried out by SDS‐PAGE. Also, sulphhydryl and disulphide groups, water‐holding capacity (WHC), water solubility index (WSI) and oil absorption capacity (OAC) were determined. No changes in total nitrogen content of pea and kidney bean seeds occurred as a result of thermal treatment. Protein solubility from raw and extruded legumes was significantly higher in saline solutions than in water in the pH range 2–10. The solubility of proteins from extruded pea and kidney bean flours was greatly decreased with respect to native flours when extraction was in buffer (pH 7.0) alone. Extraction with buffer containing 2‐mercaptoethanol (2‐ME) or sodium dodecyl sulphate (SDS), alone or in combination, greatly increased protein extractability. As a result, the relative solubility was nearly 100% in buffer with SDS and 2‐ME for both raw and extruded samples. Total and free sulphhydryl group and disulphide contents decreased significantly (P < 0.05) after extrusion cooking. Moreover, extrusion treatment caused major changes in the band patterns of the albumin and globulin fractions obtained by SDS‐PAGE. WHC and WSI of extrudates increased significantly in both peas and kidney beans. A significant reduction in OAC was observed in extruded kidney bean flour. © 2000 Society of Chemical Industry     

Distribution of fatty acids in triacylglycerols and phospholipids from peas (Pisum sativum L.)

BACKGROUND: The fatty acid distribution of triacylglycerols (TAG) and major phospholipids (PL) obtained from four varieties of peas (Pisum sativum) was investigated. The total lipids extracted from the peas were separated by thin layer chromatography into seven fractions. RESULTS: The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while hydrocarbons, steryl esters, free fatty acids and diacylglycerols (sn‐1,3 and sn‐1,2) were also present in minor proportions (5.6–9.2%). The main PL components isolated from the four varieties were phosphatidylcholine (42.3–49.2%), phosphatidylinositol (23.3–25.2%) and phosphatidylethanolamine (17.7–20.5%). Significant differences (P < 0.05) in fatty acid distribution were found for different pea varieties. Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. However, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident among the four varieties: unsaturated fatty acids were predominantly located in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in the oils of the peas. CONCLUSION: These results should be useful to both producers and consumers for the manufacture of pea foods in Japan. Copyright © 2007 Society of Chemical Industry     

Microencapsulation of bioactive compounds from mulberry (Morus alba L.) leaf extracts by protein–polysaccharide interactions

Mulberry leaf extracts were generated using four concentrations of ethanol (50%, 60%, 70%, and 95% v/v). A 60% ethanolic mulberry leaf extract (60E) yielded a high total phenolic content (TPC) and antioxidant activity using 1, 1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging and a ferric reducing antioxidant power (FRAP) assay. Coating materials were derived using a combination of soy protein isolates (SPI) and low methoxyl (LM) pectin in a 1:1 ratio. The effect of various parameters on microencapsulation, such as pH (3.5, 4.0, and 4.5) and the concentration of coating materials (2.5, 5.0 and 7.5% w/v), was studied. Microcapsules produced using 60E as a core material at pH 4.0 with 7.5% of coating material showed a high encapsulation yield, encapsulation efficiency, TPC and antioxidant activity.     

The effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in certain bread types

The aim of this study was to investigate the effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in white wheat, wheat bran and whole‐grain wheat breads. Two‐day germinated pea flour was used at 0%, 1%, 3% and 5% levels for each bread type. Acrylamide analysis was performed with liquid chromatography–mass spectrometry. Besides, colour and sensory properties of the breads were evaluated to search out the effects of pea flour substitution on the consumer acceptance. Reduction of acrylamide in white wheat bread was not found significant and addition of pea flour decreased the acceptance. However, it was found that acrylamide level can be reduced by 57% and 68% with addition of 5% pea flour in wheat bran and whole‐grain breads, respectively, without any negative impact on colour and sensory properties.     

Biological response of broiler chickens fed peas (Pisum sativum L.) expressing the bean (Phaseolus vulgaris L.) α‐amylase inhibitor transgene

The nutritive value of transgenic peas expressing an α‐amylase inhibitor (α‐Ai1) was evaluated with broiler chickens. The effects of feeding transgenic peas on the development of visceral organs associated with digestion and nutrient absorption were also examined. The chemical composition of the conventional and the transgenic peas used in this study were similar. In the two feeding trials, that were conducted normal and transgenic peas were incorporated into a maize–soybean diet at concentrations up to 500 g kg^?1. The diets were balanced to contain similar levels of apparent metabolisable energy (AME) and amino acids. In the first trial, the birds were fed the diets from 3 to 17 days post‐hatching and with levels of transgenic peas at 250 g kg^?1 or greater there was a significant reduction in body weight but an increase in feed intake resulting in deceased feed conversion efficiency. In the second trial, in which the birds were fed diets containing 300 g kg^?1 transgenic peas until 40 days of age, growth performance was significantly reduced. It was also demonstrated that the ileal starch digestibility coefficient (0.80 vs 0.42) was significantly reduced in the birds fed transgenic peas. Determination of AME and ileal digestibility of amino acids in 5‐week‐old broilers demonstrated a significant reduction in AME (12.12 vs 5.08 MJ kg^?1 DM) in the birds fed the transgenic peas. The AME value recorded for transgenic peas reflected the lower starch digestibility of this line. Ileal digestion of protein and amino acids was unaffected by treatment. Expression of α‐Ai1 in peas did not appear to affect bird health or the utilisation of dietary protein. However, the significant reduction in ileal digestion of starch in transgenic peas does reduce the utility of this feedstuff in monogastric diets where efficient energy utilisation is required. Copyright © 2006 Society of Chemical Industry     

预冷结合气调对荷兰豆冷藏期间品质的影响

研究了预冷结合气调（CA）对荷兰豆冷藏期间品质的影响。采收的荷兰豆分别在常温下放置0（立即预冷）、6、12 h（对照）后置冷库内以强制通风（1.0±0.5）℃方式预冷至中心温度下降到2℃,于（1±0.5）℃、3%O₂+5%CO₂+92%N2环境下贮藏30 d。贮藏期间每10 d测定荷兰豆的色泽（a*值）,超氧阴离子（O₂^-·）产生速率,呼吸速率,丙二醛（MDA）、叶绿素、纤维素、还原糖含量,纤维素酶（CEL）、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性。结果显示,预冷结合气调贮藏显著抑制了荷兰豆a*值、纤维素含量的上升和叶绿素含量的下降;还原糖含量略高于对照;维持了相对低的呼吸速率、O₂^-·产生速率和MDA含量;CEL、SOD和POD活性显著高于对照（p<0.05）,且立即预冷组优于6 h后预冷组和对照组。以上结果表明,立即预冷结合气调贮藏能有效维持荷兰豆的鲜绿色,延缓纤维化,抑制呼吸作用,提高抗氧化酶类活性,最终维持荷兰豆较好的品质。      

预冷对气调荷兰豆货架期品质和生理的影响

为研究不同预冷方式和气调处理对模拟货架后荷兰豆品质和生理特性的影响。分别于0、6h 和12h 三种不同放置时间后对荷兰豆进行预冷并立即建立气调(体积配比为3% O2+5% CO2+92% N2)条件1℃贮藏,荷兰豆贮藏0、10、20d 和30d 后进行2d 常温模拟货架实验。结果表明：与6h 或12h 后预冷比较,立即预冷的荷兰豆在模拟货架后呼吸作用弱,纤维素增加量小,超氧阴离子自由基和丙二醛含量保持在较低水平,抗氧化酶——过氧化物酶和超氧化物歧化酶具有较高的活力。立即预冷可有效抑制货架期荷兰豆的生理活动和更好地保持其品质。     

大豆蛋白特性对其高湿挤压纤维化产品的影响

研究大豆蛋白的特性对其高湿挤压纤维化的影响,分别选用低温脱脂豆粉、大豆分离蛋白和五个不同品种的大豆为原料进行实验。研究了氮溶解指数(NSI值)、粒度及大豆蛋白7S/11S比值等因素对高湿挤压纤维化产品特性的影响。实验结果表明,挤压原料特性对高湿挤压纤维化产品的感官质量、质构特性及微观结构产生较明显的影响。较高NSI值和较低粒径范围(0.076～0.135mm)原料的挤压产品纤维化结构较好;大豆11S球蛋白在挤压加工过程中起重要作用,提高11S球蛋白的含量,在一定程度上可以提高挤压纤维化产品的品质。      

Studies on the biological responses of rats to seed trypsin inhibitors using near-isogenic lines of Pisum sativum L (pea)

In order to determine the true antinutritional status of pea seed trypsin inhibitor (TI) proteins, pea lines are being produced that are near-isogenic except for the genetic locus, Tri, containing the TI structural genes. These lines are based on selection from the progeny of a cross between lines showing quantitative variation in TI content, as well as TI isoform and gene polymorphisms that serve as markers. Chemical analyses revealed that the composition of seeds from lines of each near-isogenic pair was extremely similar, except for a more than five-fold difference in TI content. Such lines provide material that is superior to the diverse lines previously used for nutritional assessment of pea TI. The specific biological effects of pea TI were studied by including the near-isogenic lines in standardised rat diets. The results indicated that TI content was correlated with a significant negative effect on protein digestibility and biological value. The difference in TI content of the pea seeds was reflected in the relative activity of pancreatic chymotrypsin whereas the activities of trypsin, lipase and amylase were less clearly affected. © 1999 Society of Chemical Industry     

Effect of proteins on the formation of starch–lipid complexes during extrusion cooking of wheat flour with the addition of oleic acid

The formation of starch–lipid complexes plays an important role in extruded products. The effect of gluten proteins on thermal conditions at which the starch–lipid complexes formed during extrusion cooking of wheat flour with the addition of oleic acid was evaluated, considering wheat starch as a reference. The presence of gluten proteins in wheat flour extrudates brought about a reduction of the formation of starch–lipid complexes compared to blend of wheat starch and oleic acid extruded at the same operating conditions (melting enthalpy: 0.4 vs. 1.6 kJ kg^?1). Moreover, the lubricant effect of oleic acid observed during extrusion of wheat starch (low values of specific mechanical energy and residence time) was not found during extrusion of wheat flour with addition of oleic acid because of the interaction between gluten proteins and oleic acid. This research points out the importance of proteins on biopolymer modifications and their effect on extrudate quality.     

Effects of protein–lipid and starch–lipid complexes on textural characteristics of extrudates based on wheat flour with the addition of oleic acid

The knowledge of biopolymer changes by extrusion is very important for a wide range of industrial applications that spreads from extruded food to biodegradable packaging. In this article, the formation of starch–lipid and lipid–protein complexes that occurred during the extrusion cooking of wheat flour with the addition of fatty acids was studied. Results showed that the highest barrel temperature (128.3 °C) promoted the formation of starch–lipid complexes in samples made up of wheat starch and wheat flour with the addition of fatty acids. The maximum formation of protein–lipid complexes (68% fatty acid bound to protein) was observed at the highest barrel temperature and water feed content (<22%). This study is a prerequisite for the optimisation of production of expanded extrudates made up of wheat flour and fatty ingredients and for the study of a biodegradable packaging based on by‐product of milling wheat (and fat).     

Effect of treatment with α‐galactosidase,tannase or a cell‐wall‐degrading enzyme complex on the nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour

The effect of treatment with α‐galactosidase, tannase or a cell‐wall‐degrading enzyme complex under optimal conditions of pH, temperature and length of incubation time on the chemical composition and nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour was studied. Soaking of pea flours in combination with enzyme treatment led to reductions of 77–90% in the levels of α‐galactosides, and of 60–80% in the levels of trypsin inhibitor activity, increasing the content of total available sugars, which was highest in the pea flour treated with the cell‐wall‐degrading enzyme complex. All the treatments assayed caused a significant improvement in daily food intake, whereas the nutritive utilisation of protein was not increased in any of the pea products tested when compared to the raw pea flour. However, all the soaking and enzymatic treatments led to a significant improvement in daily weight gain associated with a higher dietary intake of food and total available sugars. Copyright © 2007 Society of Chemical Industry     

Effect of mungbean [Vigna radiata (L.) Wilczek] protein isolates on the microbial transglutaminase‐mediated porcine myofibrillar protein gels at various salt concentrations

This study was performed to investigate the effects of mungbean protein isolates (MPI) as a meat/water binder on the MTGase‐mediated porcine myofibrillar protein (MP) gels at 0.15, 0.3, and 0.45 m salt concentrations. The general property of MP gel was evaluated by pH, cooking loss (CL) (%) and gel strength (gf). Protein–protein interactions among MPI, MTGase, and MP during cooking were also assessed using gel electrophoresis, thermal analysis and microstructure. When salt content was reduced, gel CL (%; P < 0.05) was increased while pH and gel strength (gf) values were decreased (P < 0.05). Addition of MTGase to MP increased pH, CL (%), and gel strength (gf) values, while co‐addition of MTGase and MPI induced synergistic effects on the MP gel strength (gf; ≥0.3 m salt concentration; P < 0.05). In scanning electron micrograph images, increase of salt concentrations made MP gels more swollen and interwoven or conglomerated, regardless of treatment. In conclusion, addition of MPI and MTGase strengthened gel‐forming ability and improved cooking yield of MP gel at salt concentration (≥0.3 m ).     

Effect of different technological processes on the chemical composition of myrtle (<Emphasis Type="Italic">Myrtus communis</Emphasis> L.) alcoholic extracts

Several technological processes were applied to improve the extraction efficiency in the production of myrtle (Myrtus communis L.) liqueur. The variations in the chemical composition of myrtle hydroalcoholic extracts were monitored in a laboratory scale for 40 days after the application of: double dose of berries; ultrasonic extraction; enzymes, to improve either the color or aroma extraction; and atmosphere saturated with nitrogen to improve the stability against oxidative degradations during extraction. Moreover, freezing at −20 °C was applied to myrtle berries as a technological strategy to prolong the use of berries, and macerates were obtained after 4, 8, and 12 months. Chemical investigation of macerates was performed using different analytical methods such as GC and GC-MS for the volatile compounds, HPLC-PDA for free anthocyanins, and spectrophotometric analysis for CIE L*a*b* coordinates and total anthocyanins. Dry matter and pH were also monitored during maceration. Among the different technological processes, the nitrogen-modified atmosphere was the most suitable technique to be applied in industrial scale. An industrial trial was applied with this process and alcoholic extracts and liqueurs have been obtained. The liqueur maintained a higher amount of anthocyanins, better CIE L*a*b* parameters and superior organoleptic characteristics compared to the traditional storage.